// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <stddef.h>
#include <sys/lock.h>
#include "esp_attr.h"
#include "esp_deep_sleep.h"
#include "esp_log.h"
#include "rom/cache.h"
#include "rom/rtc.h"
#include "rom/uart.h"
#include "soc/cpu.h"
#include "soc/rtc_cntl_reg.h"
#include "soc/dport_reg.h"
#include "driver/rtc_io.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "rtc.h"
#include "sdkconfig.h"

/**
 * Internal structure which holds all requested deep sleep parameters
 */
typedef struct {
    esp_deep_sleep_pd_option_t pd_options[ESP_PD_DOMAIN_MAX];
    uint64_t sleep_duration;
    uint32_t wakeup_triggers : 11;
    uint32_t ext1_trigger_mode : 1;
    uint32_t ext1_rtc_gpio_mask : 18;
    uint32_t ext0_trigger_level : 1;
    uint32_t ext0_rtc_gpio_num : 5;
} deep_sleep_config_t;

static deep_sleep_config_t s_config = {
    .pd_options = { ESP_PD_OPTION_AUTO, ESP_PD_OPTION_AUTO, ESP_PD_OPTION_AUTO },
    .wakeup_triggers = 0
};

/* Updating RTC_MEMORY_CRC_REG register via set_rtc_memory_crc()
   is not thread-safe. */
static _lock_t lock_rtc_memory_crc;

static const char* TAG = "deepsleep";

static uint32_t get_power_down_flags();
static void ext0_wakeup_prepare();
static void ext1_wakeup_prepare();

/* Wake from deep sleep stub
   See esp_deepsleep.h esp_wake_deep_sleep() comments for details.
*/
esp_deep_sleep_wake_stub_fn_t esp_get_deep_sleep_wake_stub(void)
{
    _lock_acquire(&lock_rtc_memory_crc);
    uint32_t stored_crc = REG_READ(RTC_MEMORY_CRC_REG);
    set_rtc_memory_crc();
    uint32_t calc_crc = REG_READ(RTC_MEMORY_CRC_REG);
    REG_WRITE(RTC_MEMORY_CRC_REG, stored_crc);
    _lock_release(&lock_rtc_memory_crc);

    if(stored_crc == calc_crc) {
        return (esp_deep_sleep_wake_stub_fn_t)REG_READ(RTC_ENTRY_ADDR_REG);
    } else {
        return NULL;
    }
}

void esp_set_deep_sleep_wake_stub(esp_deep_sleep_wake_stub_fn_t new_stub)
{
    _lock_acquire(&lock_rtc_memory_crc);
    REG_WRITE(RTC_ENTRY_ADDR_REG, (uint32_t)new_stub);
    set_rtc_memory_crc();
    _lock_release(&lock_rtc_memory_crc);
}

void RTC_IRAM_ATTR esp_default_wake_deep_sleep(void) {
    /* Clear MMU for CPU 0 */
    REG_SET_BIT(DPORT_PRO_CACHE_CTRL1_REG, DPORT_PRO_CACHE_MMU_IA_CLR);
    REG_CLR_BIT(DPORT_PRO_CACHE_CTRL1_REG, DPORT_PRO_CACHE_MMU_IA_CLR);
#if CONFIG_ESP32_DEEP_SLEEP_WAKEUP_DELAY > 0
    // ROM code has not started yet, so we need to set delay factor
    // used by ets_delay_us first.
    ets_update_cpu_frequency(ets_get_detected_xtal_freq() / 1000000);
    // This delay is configured in menuconfig, it can be used to give
    // the flash chip some time to become ready.
    ets_delay_us(CONFIG_ESP32_DEEP_SLEEP_WAKEUP_DELAY);
#endif
}

void __attribute__((weak, alias("esp_default_wake_deep_sleep"))) esp_wake_deep_sleep(void);

void esp_deep_sleep(uint64_t time_in_us)
{
    esp_deep_sleep_enable_timer_wakeup(time_in_us);
    esp_deep_sleep_start();
}

void IRAM_ATTR esp_deep_sleep_start()
{
    // Decide which power domains can be powered down
    uint32_t pd_flags = get_power_down_flags();

    // Configure pins for external wakeup
    if (s_config.wakeup_triggers & EXT_EVENT0_TRIG_EN) {
        ext0_wakeup_prepare();
    }
    if (s_config.wakeup_triggers & EXT_EVENT1_TRIG_EN) {
        ext1_wakeup_prepare();
    }
    // TODO: move timer wakeup configuration into a similar function
    // once rtc_sleep is opensourced.

    // Flush UARTs so that output is not lost due to APB frequency change
    uart_tx_wait_idle(0);
    uart_tx_wait_idle(1);
    uart_tx_wait_idle(2);

    if (esp_get_deep_sleep_wake_stub() == NULL) {
        esp_set_deep_sleep_wake_stub(esp_wake_deep_sleep);
    }

    rtc_set_cpu_freq(CPU_XTAL);
    uint32_t cycle_h = 0;
    uint32_t cycle_l = 0;
    // For timer wakeup, calibrate clock source against main XTAL
    // This is hardcoded to use 150kHz internal oscillator for now
    if (s_config.sleep_duration > 0) {
        uint32_t period = rtc_slowck_cali(CALI_RTC_MUX, 128);
        rtc_usec2rtc(s_config.sleep_duration >> 32, s_config.sleep_duration & UINT32_MAX,
                period, &cycle_h, &cycle_l);
    }
    // Enter deep sleep
    rtc_slp_prep_lite(pd_flags, 0);
    rtc_sleep(cycle_h, cycle_l, s_config.wakeup_triggers, 0);
    // Because RTC is in a slower clock domain than the CPU, it
    // can take several CPU cycles for the sleep mode to start.
    while (1) {
        ;
    }
}

void system_deep_sleep(uint64_t) __attribute__((alias("esp_deep_sleep")));

esp_err_t esp_deep_sleep_enable_ulp_wakeup()
{
#ifdef CONFIG_ULP_COPROC_ENABLED
    s_config.wakeup_triggers |= RTC_SAR_TRIG_EN;
    return ESP_OK;
#else
    return ESP_ERR_INVALID_STATE;
#endif
}

esp_err_t esp_deep_sleep_enable_timer_wakeup(uint64_t time_in_us)
{
    s_config.wakeup_triggers |= RTC_TIMER_EXPIRE_EN;
    s_config.sleep_duration = time_in_us;
    return ESP_OK;
}

esp_err_t esp_deep_sleep_enable_ext0_wakeup(gpio_num_t gpio_num, int level)
{
    if (level < 0 || level > 1) {
        return ESP_ERR_INVALID_ARG;
    }
    if (!RTC_GPIO_IS_VALID_GPIO(gpio_num)) {
        return ESP_ERR_INVALID_ARG;
    }
    s_config.ext0_rtc_gpio_num = rtc_gpio_desc[gpio_num].rtc_num;
    s_config.ext0_trigger_level = level;
    s_config.wakeup_triggers |= RTC_EXT_EVENT0_TRIG_EN;
    return ESP_OK;
}

static void ext0_wakeup_prepare()
{
    int rtc_gpio_num = s_config.ext0_rtc_gpio_num;
    // Set GPIO to be used for wakeup
    REG_SET_FIELD(RTC_IO_EXT_WAKEUP0_REG, RTC_IO_EXT_WAKEUP0_SEL, rtc_gpio_num);
    // Set level which will trigger wakeup
    SET_PERI_REG_BITS(RTC_CNTL_EXT_WAKEUP_CONF_REG, 0x1,
            s_config.ext0_trigger_level, RTC_CNTL_EXT_WAKEUP0_LV_S);
    // Find GPIO descriptor in the rtc_gpio_desc table and configure the pad
    for (size_t gpio_num = 0; gpio_num < GPIO_PIN_COUNT; ++gpio_num) {
        const rtc_gpio_desc_t* desc = &rtc_gpio_desc[gpio_num];
        if (desc->rtc_num == rtc_gpio_num) {
            REG_SET_BIT(desc->reg, desc->mux);
            SET_PERI_REG_BITS(desc->reg, 0x3, 0, desc->func);
            REG_SET_BIT(desc->reg, desc->slpsel);
            REG_SET_BIT(desc->reg, desc->slpie);
            break;
        }
    }
}

esp_err_t esp_deep_sleep_enable_ext1_wakeup(uint64_t mask, esp_ext1_wakeup_mode_t mode)
{
    if (mode > ESP_EXT1_WAKEUP_ANY_HIGH) {
        return ESP_ERR_INVALID_ARG;
    }
    // Translate bit map of GPIO numbers into the bit map of RTC IO numbers
    uint32_t rtc_gpio_mask = 0;
    for (int gpio = 0; mask; ++gpio, mask >>= 1) {
        if ((mask & 1) == 0) {
            continue;
        }
        if (!RTC_GPIO_IS_VALID_GPIO(gpio)) {
            ESP_LOGE(TAG, "Not an RTC IO: GPIO%d", gpio);
            return ESP_ERR_INVALID_ARG;
        }
        rtc_gpio_mask |= BIT(rtc_gpio_desc[gpio].rtc_num);
    }
    s_config.ext1_rtc_gpio_mask = rtc_gpio_mask;
    s_config.ext1_trigger_mode = mode;
    s_config.wakeup_triggers |= RTC_EXT_EVENT1_TRIG_EN;
    return ESP_OK;
}

static void ext1_wakeup_prepare()
{
    // Configure all RTC IOs selected as ext1 wakeup inputs
    uint32_t rtc_gpio_mask = s_config.ext1_rtc_gpio_mask;
    for (int gpio = 0; gpio < GPIO_PIN_COUNT && rtc_gpio_mask != 0; ++gpio) {
        int rtc_pin = rtc_gpio_desc[gpio].rtc_num;
        if ((rtc_gpio_mask & BIT(rtc_pin)) == 0) {
            continue;
        }
        const rtc_gpio_desc_t* desc = &rtc_gpio_desc[gpio];
        // Route pad to RTC
        REG_SET_BIT(desc->reg, desc->mux);
        SET_PERI_REG_BITS(desc->reg, 0x3, 0, desc->func);
        // Pad configuration depends on RTC_PERIPH state in sleep mode
        if (s_config.pd_options[ESP_PD_DOMAIN_RTC_PERIPH] == ESP_PD_OPTION_ON) {
            // set input enable in sleep mode
            REG_SET_BIT(desc->reg, desc->slpie);
            // allow sleep status signal to control IE/SLPIE mux
            REG_SET_BIT(desc->reg, desc->slpsel);
        } else {
            // RTC_PERIPH will be disabled, so need to enable input and
            // lock pad configuration. Pullups/pulldowns also need to be disabled.
            REG_SET_BIT(desc->reg, desc->ie);
            REG_CLR_BIT(desc->reg, desc->pulldown);
            REG_CLR_BIT(desc->reg, desc->pullup);
            REG_SET_BIT(RTC_CNTL_HOLD_FORCE_REG, desc->hold);
        }
        // Keep track of pins which are processed to bail out early
        rtc_gpio_mask &= ~BIT(rtc_pin);
    }
    // Clear state from previous wakeup
    REG_SET_BIT(RTC_CNTL_EXT_WAKEUP1_REG, RTC_CNTL_EXT_WAKEUP1_STATUS_CLR);
    // Set pins to be used for wakeup
    REG_SET_FIELD(RTC_CNTL_EXT_WAKEUP1_REG, RTC_CNTL_EXT_WAKEUP1_SEL, s_config.ext1_rtc_gpio_mask);
    // Set logic function (any low, all high)
    SET_PERI_REG_BITS(RTC_CNTL_EXT_WAKEUP_CONF_REG, 0x1,
            s_config.ext1_trigger_mode, RTC_CNTL_EXT_WAKEUP1_LV_S);
}

uint64_t esp_deep_sleep_get_ext1_wakeup_status()
{
    int wakeup_reason = REG_GET_FIELD(RTC_CNTL_WAKEUP_STATE_REG, RTC_CNTL_WAKEUP_CAUSE);
    if (wakeup_reason != RTC_EXT_EVENT1_TRIG) {
        return 0;
    }
    uint32_t status = REG_GET_FIELD(RTC_CNTL_EXT_WAKEUP1_STATUS_REG, RTC_CNTL_EXT_WAKEUP1_STATUS);
    // Translate bit map of RTC IO numbers into the bit map of GPIO numbers
    uint64_t gpio_mask = 0;
    for (int gpio = 0; gpio < GPIO_PIN_COUNT; ++gpio) {
        if (!RTC_GPIO_IS_VALID_GPIO(gpio)) {
            continue;
        }
        int rtc_pin = rtc_gpio_desc[gpio].rtc_num;
        if ((status & BIT(rtc_pin)) == 0) {
            continue;
        }
        gpio_mask |= BIT(gpio);
    }
    return gpio_mask;
}

esp_err_t esp_deep_sleep_pd_config(esp_deep_sleep_pd_domain_t domain,
                                   esp_deep_sleep_pd_option_t option)
{
    if (domain >= ESP_PD_DOMAIN_MAX || option > ESP_PD_OPTION_AUTO) {
        return ESP_ERR_INVALID_ARG;
    }
    s_config.pd_options[domain] = option;
    return ESP_OK;
}

static uint32_t get_power_down_flags()
{
    // Where needed, convert AUTO options to ON. Later interpret AUTO as OFF.

    // RTC_SLOW_MEM is needed only for the ULP.
    // If RTC_SLOW_MEM is Auto, and ULP wakeup isn't enabled, power down RTC_SLOW_MEM.
    if (s_config.pd_options[ESP_PD_DOMAIN_RTC_SLOW_MEM] == ESP_PD_OPTION_AUTO) {
        if (s_config.wakeup_triggers & RTC_SAR_TRIG_EN) {
            s_config.pd_options[ESP_PD_DOMAIN_RTC_SLOW_MEM] = ESP_PD_OPTION_ON;
        }
    }

    // RTC_FAST_MEM is needed for deep sleep stub.
    // If RTC_FAST_MEM is Auto, keep it powered on, so that deep sleep stub
    // can run.
    // In the new chip revision, deep sleep stub will be optional,
    // and this can be changed.
    if (s_config.pd_options[ESP_PD_DOMAIN_RTC_FAST_MEM] == ESP_PD_OPTION_AUTO) {
        s_config.pd_options[ESP_PD_DOMAIN_RTC_FAST_MEM] = ESP_PD_OPTION_ON;
    }

    // RTC_PERIPH is needed for EXT0 wakeup and for ULP.
    // If RTC_PERIPH is auto, and both EXT0 and ULP aren't enabled,
    // power down RTC_PERIPH.
    if (s_config.pd_options[ESP_PD_DOMAIN_RTC_PERIPH] == ESP_PD_OPTION_AUTO) {
        if (s_config.wakeup_triggers &
                (RTC_SAR_TRIG_EN | RTC_EXT_EVENT0_TRIG_EN)) {
            s_config.pd_options[ESP_PD_DOMAIN_RTC_PERIPH] = ESP_PD_OPTION_ON;
        }
    }

    const char* option_str[] = {"OFF", "ON", "AUTO(OFF)" /* Auto works as OFF */};
    ESP_LOGD(TAG, "RTC_PERIPH: %s, RTC_SLOW_MEM: %s, RTC_FAST_MEM: %s",
            option_str[s_config.pd_options[ESP_PD_DOMAIN_RTC_PERIPH]],
            option_str[s_config.pd_options[ESP_PD_DOMAIN_RTC_SLOW_MEM]],
            option_str[s_config.pd_options[ESP_PD_DOMAIN_RTC_FAST_MEM]]);

    // Prepare flags based on the selected options
    uint32_t pd_flags = DEEP_SLEEP_PD_NORMAL;
    if (s_config.pd_options[ESP_PD_DOMAIN_RTC_FAST_MEM] != ESP_PD_OPTION_ON) {
        pd_flags |= DEEP_SLEEP_PD_RTC_FAST_MEM;
    }
    if (s_config.pd_options[ESP_PD_DOMAIN_RTC_SLOW_MEM] != ESP_PD_OPTION_ON) {
        pd_flags |= DEEP_SLEEP_PD_RTC_SLOW_MEM;
    }
    if (s_config.pd_options[ESP_PD_DOMAIN_RTC_PERIPH] != ESP_PD_OPTION_ON) {
        pd_flags |= DEEP_SLEEP_PD_RTC_PERIPH;
    }
    return pd_flags;
}
